Whisk the sugar, lemon zest, baking blend and flour in a medium bowl. Add the raspberries, lemon juice and butter and toss to coat. Set aside.
Make the oat layer:
Pre-heat oven to 350 degrees. Line an 8″ x 8″ baking pan with parchment paper, leaving an overhang on both sides. Beat all of the ingredients till fully incorporated.
Place half of the oat mixture into your baking pan and press in evenly. Drain any excess liquid from your raspberry filling and spread on top of the oat mixture. Crumble the remaining oat mixture on top. Bake for 40 – 50 minutes, till golden brown. Cool completely in the pan on a wire rack. For the neatest cuts I like to refrigerate the cooled bars overnight.
Use your parchment sling to transfer the bars to a cutting board and cut into squares.
Notes
You can substitute the all-purpose flour and oats for a cup-for-cup blend and GF oats.
To make vegan squares replace the butter with a non-dairy spread.
Swap the baking blend for an equal amount of cinnamon (or your favorite baking spice).
You can replace the filling with 1 1/2 - 2 cups of any preserve or fruit spread.
To scale up the recipe, double the ingredients and bake in a 9 x 13 pan (baking time may need to be increased accordingly).